RESUMO

The first isocoumarin isolated from the methylene chloride extract of Paepalanthus bromelioides, named paepalantine (isocoumarin 1), was found to have antimicrobial activity; but, it is mutagenic clastogenic and cytotoxic. Two other isocoumarins, paepalantine-9-O-beta-D-glucopyranoside (isocoumarin 2) and paepalantine-9-O-beta-D-allopyranosyl(1 --> 6) glucopyranoside (isocoumarin 3) were isolated from the ethanolic extract. A fourth new isocoumarin, also isolated from the methylene chloride extract of the capitula of P. bromelioides, was characterized as an 8-8' dimer of paepalantine and denominated isocoumarin 4. The abilities of isocoumarins 2, 3 and 4 to induce mutations in Salmonella typhimurium strains TA97a, TA98, TA100 and TA102 were investigated. Mutagenic activity was observed in strain TA97a treated with isocoumarin 2 in the presence of S9 mixture. The substitution of H at position 9 by glucose or glucose-allose caused reductions in the mutagenic activities of paepalantine, indicating this to be an important site for these properties.

Assuntos

Cumarínicos/efeitos adversos , Eriocaulaceae , Glicosídeos/efeitos adversos , Mutagênicos/isolamento & purificação , Animais , Cumarínicos/química , Cumarínicos/isolamento & purificação , Cricetinae , Dimerização , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Glicosídeos/química , Glicosídeos/isolamento & purificação , Isocumarinas , Cloreto de Metileno/química , Testes de Mutagenicidade , Mutagênicos/efeitos adversos , Mutagênicos/química , Extratos Vegetais/efeitos adversos , Extratos Vegetais/química , Plantas Medicinais/química , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Especificidade da Espécie , Fuso Acromático/efeitos dos fármacos , Relação Estrutura-Atividade